Multigenerational maternal obesity increases the incidence of HCC in offspring via miR-27a-3p.

Obesity is an independent risk factor for malignancies, including hepatocellular carcinoma (HCC). However, it remains unknown whether maternal obesity affects the incidence of HCC in offspring. Thus, we aimed to investigate this association and its underlying mechanisms. Diethylnitrosamine (DEN) was used to induce HCC in a high-fat diet (HFD)-induced multigenerational obesity model. RNA-sequencing was performed to identify the genes and microRNAs (miRNAs) that were altered over generations. The role of the miR-27a-3p-Acsl1/Aldh2 axis in HCC was evaluated in cell lines and HCC-bearing nude mice, and its intergenerational impact was studied in pregnant mice and their offspring. Under HFD stress, maternal obesity caused susceptibility of offspring to DEN-induced HCC, and such susceptibility was cumulative over generations. We identified that Acsl1 and Aldh2, direct targets of miR-27a-3p, were gradually changed over generations. Under hyperlipidemic conditions, downregulation of Acsl1 and Aldh2 increased cell proliferation (in vitro) or tumor growth (in vivo) in synergy. Intratumor injection of an miR-27a-3p agomir exacerbated tumor growth by downregulating Acsl1 and Aldh2; while intratumor injection of an miR-27a-3p antagomir had the opposite effect. Moreover, serum miR-27a-3p levels gradually increased in the HFD-fed maternal lineage over generations. Injecting pregnant mice with an miR-27a-3p agomir not only upregulated hepatic miR-27a-3p and downregulated Acsl1/Aldh2 in offspring (fetus, young and adult stages), but also exacerbated HCC development in DEN-treated offspring. In human HCC, upregulated miR-27a-3p and downregulated Acsl1/Aldh2 were negatively correlated with survival on TCGA analysis; while, hepatic miR-27a-3p was negatively correlated with Acsl1/Aldh2 expression in tumor/non-tumor tissues from fatty/non-fatty livers. Maternal obesity plays a role in regulating cumulative susceptibility to HCC development in offspring over multiple generations through the miR-27a-3p-Acsl1/Aldh2 axis. It is not currently known how maternal obesity affects the incidence of liver cancer in offspring. In this study, we identified a microRNA (miR-27a-3p) that was upregulated in obese mothers and could be passed on to their offspring. This microRNA enhanced the risk of liver cancer in offspring by regulating 2 genes (Acsl1 and Aldh2). This mechanism could be a future therapeutic target.

Sun Y ，Wang Q ，Zhang Y ，Geng M ，Wei Y ，Liu Y ，Liu S ，Petersen RB ，Yue J ，Huang K ，Zheng L ... -  《-》

Metabolic pathway analyses identify proline biosynthesis pathway as a promoter of liver tumorigenesis.

Under the regulation of various oncogenic pathways, cancer cells undergo adaptive metabolic programming to maintain specific metabolic states that support their uncontrolled proliferation. As it has been difficult to directly and effectively inhibit oncogenic signaling cascades with pharmaceutical compounds, focusing on the downstream metabolic pathways that enable indefinite growth may provide therapeutic opportunities. Thus, we sought to characterize metabolic changes in hepatocellular carcinoma (HCC) development and identify metabolic targets required for tumorigenesis. We compared gene expression profiles of Morris Hepatoma (MH3924a) and DEN (diethylnitrosamine)-induced HCC models to those of liver tissues from normal and rapidly regenerating liver models, and performed gain- and loss-of-function studies of the identified gene targets for their roles in cancer cell proliferation in vitro and in vivo. The proline biosynthetic enzyme PYCR1 (pyrroline-5-carboxylate reductase 1) was identified as one of the most upregulated genes in the HCC models. Knockdown of PYCR1 potently reduced cell proliferation of multiple HCC cell lines in vitro and tumor growth in vivo. Conversely, overexpression of PYCR1 enhanced the proliferation of the HCC cell lines. Importantly, PYCR1 expression was not elevated in the regenerating liver, and KD or overexpression of PYCR1 had no effect on proliferation of non-cancerous cells. Besides PYCR1, we found that additional proline biosynthetic enzymes, such as ALDH18A1, were upregulated in HCC models and also regulated HCC cell proliferation. Clinical data demonstrated that PYCR1 expression was increased in HCC, correlated with tumor grade, and was an independent predictor of clinical outcome. Enhanced expression of proline biosynthetic enzymes promotes HCC cell proliferation. Inhibition of PYCR1 or ALDH18A1 may be a novel therapeutic strategy to target HCC. Even with the recently approved immunotherapies against liver cancer, currently available medications show limited clinical benefits or efficacy in the majority of patients. As such, it remains a top priority to discover new targets for effective liver cancer treatment. Here, we identify a critical role for the proline biosynthetic pathway in liver cancer development, and demonstrate that targeting key proteins in the pathway, namely PYCR1 and ALDH18A1, may be a novel therapeutic strategy for liver cancer.

Ding Z ，Ericksen RE ，Escande-Beillard N ，Lee QY ，Loh A ，Denil S ，Steckel M ，Haegebarth A ，Wai Ho TS ，Chow P ，Toh HC ，Reversade B ，Gruenewald S ，Han W ... -  《-》

MicroRNA-27a-3p inhibits cell viability and migration through down-regulating DUSP16 in hepatocellular carcinoma.

MicroRNA (miRNA or miR) has been shown to play an important role in the initiation and development in many different cancers. Here, we demonstrated down-regulated expression of miR-27a-3p in hepatocellular carcinoma (HCC) tissues in comparison with that in adjacent normal liver tissues based on the TCGA database. Cells viability and apoptosis was measured by CCK-8 and flow cytometry assay. Cell invasion and migration was measured by Transwell and wound healing assay. The effect of miR-27a-3p on DUSP16 expression was evaluated by luciferase assays, and western blot assay. miR-27a-3p up-regulation by transfection with miR-27a-3p mimics attenuated SMMC-7721 and HepG2 cell viability, invasion as well as migration, obviously. Moreover, we found that dual specificity phosphatase 16 (DUSP16), also known as mitogen-activated protein kinase phosphatase 7 (MKP-7), is a target of miR-27a-3p. DUSP16 expression was obvious decrease by miR-27a-3p at both transcriptional and protein levels in both SMMC-7721 and HepG2 cells. DUSP16 expression in tissues of HCC was up-regulated in comparison with that in tissues of adjacent liver based on the TCGA database. Overexpression of DUSP16 significantly reversed the cell changes in viability, invasion and migration which resulted from miR-27a-3p up-regulation in SMMC-7721 and HepG2 cells. Our findings contribute to current understanding of the functions of miR-27a-3p and suggest a mechanism by which miR-27a-3p plays an anti-tumor role in the development of HCC by targeting DUSP16.

Li JM ，Zhou J ，Xu Z ，Huang HJ ，Chen MJ ，Ji JS ... -  《-》

The oncogenic miR-27a/BTG2 axis promotes obesity-associated hepatocellular carcinoma by mediating mitochondrial dysfunction.

Su Q ，Xu ZX ，Xiong ML ，Li HY ，Xu MY ，Luo SZ ... -  《-》

Exosomes secreted by M2 macrophages promote cancer stemness of hepatocellular carcinoma via the miR-27a-3p/TXNIP pathways.

Accumulating evidence has suggested that microRNAs (miRNAs) derived from M2 macrophage-derived exosomes (M2 exosomes) can regulate the progression of hepatocellular carcinoma (HCC). Nevertheless, the effect of miR-27a-3p derived from M2 exosomes on HCC has not been reported. We aim to explore the role of M2 exosomal miR-27a-3p in the cancer stemness of HCC via regulating thioredoxin-interacting protein (TXNIP). Exosomes were extracted from transfected M2 macrophages and were then co-cultured with HCC cells. Expression of miR-27a-3p and TXNIP, stemness, proliferation, drug resistance, migration, invasion and in vivo tumorigenicity of HCC cells were determined to assess the role of M2 exosomal miR-27a-3p in HCC. The binding relationship between miR-27a-3p and TXNIP was detected. MiR-27a-3p was upregulated and TXNIP was downregulated in HCC cells, and M2 exosomes further upregulated miR-27a-3p. The upregulated M2 exosomal miR-27a-3p promoted stemness, proliferation, drug resistance, migration, invasion and in vivo tumorigenicity of HCC cells. TXNIP was confirmed as a target gene of miR-27a-3p. M2 macrophages-derived exosomal miR-27a-3p promotes cancer stemness of HCC via downregulating TXNIP.

Li W ，Xin X ，Li X ，Geng J ，Sun Y ... -  《-》